Welding brass clock gear.

I have a clock wheel/gear with extensive wear in the spokes from the click spring. It needs to be welded.
is there anyone on here who lives in the Northern suburbs of Sydney that can do this job? Covid19 is limiting my travelling distance
Attachment 387778

That looks like a brazing job, but I don't know for sure if you can braze brass (because of the zinc content). Silver soldering would be the choice of process, but then it doesn't look "right" because the repair will be silver in colour....
How big and how heavy is the wheel? It looks like a clock tower clockwork..

Thanks for the reply.
Silver soldering in a brass piece has been suggested as has filling it with brass weld. Silver soldering a brass piece seems to be the simplest solution but as you say you will see lines of silver solder hence my search for someone who can weld brass.
The wheel/gear is right in the guts of the clock and hard to measure but it’s around 80mm diameter so not that large.
i wouldn’t mind getting a new one made either but that could be expensive and I’d have to find someone that can do it.

Hi. I did a little research on brass welding. It seems that silicon bronze and aluminium bronze both have lower melting temperature than brass. So brass can be brazed. The process that works is TIG brazing.
So you can try and find someone in Sydney to learn brass TIG brazing and then have a go at your gear.
If you are unsuccessful or are game, I'm certainly going to have a play now that my interest has been stimulated. I'm quite good at TIG welding and brazing, but have never tried brass. I'm happy to let you know how I go.
If I can get it to work ok, you could post me the gear for repairing and I'll post it back when done.
As long as you are clear that this may fail!
"Brass" is a very generic term for all kinds of zinc and copper containing metal alloys, so no guarantees that the brass I can practice on will behave like your gear....

Cheers
Joe

Thanks for the offer Joe.
The problem is the clock is worth some decent $$$$$ and if this gear fails the clock is useless.
think I”ll go down the Silver solder route.
BTW clock gears are made from a specific brass called Alloy 353.

Cheers

Sounds like a safe plan.
I'll post here how I go brazing brass, just for posterity....

Cheers
Joe

Ok. First go at TIG brazing brass...
Firstly, I have no idea what kind of brass alloy I have here. It is 2mm thick.
Secondly, the temperature is very critical.
The upside is that you can hear and see the zinc boiling and outgassing immediately when too hot.
Silicon bronze seems to wet the surface easiest.
Phosphor bronze just ball up on the surface.
Aluminium bronze seems to fuse rather than braze.
I even tried 15% silver solder. Which kind of works, but is impossible to keep at a low enough temperature with TIG.
Lastly, ALL of the attempts melted the brass coupon right through behind the beads (last photo is the back side of the workpiece).
I will try a few different kinds of brass scrap to see if they behave differently.
My overall assessment after this first try is that there are too many variables to do this 'routinely'...
I would certainly NOT try this on a valuable or critical piece!https://uploads.tapatalk-cdn.com/202...65915522ea.jpghttps://uploads.tapatalk-cdn.com/202...b7b95487f7.jpghttps://uploads.tapatalk-cdn.com/202...4d3a93d9c3.jpg

Cheers
Joe

Find some one close who can braze it with a torch, it is commonly done by watch makers, also re building teeth etc. I would do it except I am in SA.
either way it will have to come out of the clock.

Quote:

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Originally Posted by China

Find some one close who can braze it with a torch, it is commonly done by watch makers, also re building teeth etc. I would do it except I am in SA.
either way it will have to come out of the clock.

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I am waiting on some other parts to come from Holland before getting it pulled down for repairs which will include the wheel/gear. I’m just forward planning at the moment.

The clock gear has been repaired.

Attachment 388661

Fantastic!
But....
How? Who? Where? 😁

The old worn sections, which had been repaired before(brass pieces soft soldered in- actually visible in my first picture) were cut out and new brass sections silver soldered in.
The guy did a great job.

This is one of those situations where it is really important to know what you can do yourself cos you already know how, what you should have a go at because you probably know as much as anyone else, what would be a great skill to learn and failure is not a disaster, and when you have to find and trust an expert..

Give the guy a plug for future reference.